FEM is long considered as an efficient tool. Not many finite element software have the DEM element for analysis. So, what is the basic difference that could make DEM as a strong tool for analysis?
By DEM if you mean Discrete Element Method, then it is a tool to show motion in fluid etc. DEM is always combined with FEM or a mesh free method.DEM is effective when your solution methodology is good.
In comparison with Finite Element Method (FEM), DEM makes large displacements between elements easy to simulate. In addition, DEM surpasses FEM when
dealing with discontinuous problems where FEM becomes computationally demanding.
In mineral processing, FEM has long been considered as an efficient modelling tool. However, in grinding mills, The FEM has been limited to macro-modelling where it is used for simulating the interaction between the mill structure and the charge, (the charge is treated as a continuum). The model has also been used for predicting the pulp-liquid flow, pressure and the stress-strain behaviour of the mill structure as a result of the charge motion.
On the other hand, the DEM gives a look into the micro-mechanical interactions of the particles within the charge. The model can provide data on the motion of the particles within the charge, particle collision forces, energy loss spectra and power consumption, which is the data important for improving mill efficiency and gaining more understanding of the grinding kinetics.
FEM is a numerical method for continuum materials where in DEM don't need to this assumption.FEM is an element based approach where DEM is a particle based approach.DEM is most efficient and accurate method than FEM due to consideration of compatibility equations,constitutive relations and linear response in FEM .
FEM... is a continuum approach, the constitutive behavior of granular matter is described by constitutive laws, commonly expressed in the form of differential equations that relate mechanical field variables (e.g. stress and strain). occupies. As a result, the behavior of individual particles is ignored.
DEM ... In contrast to the continuum approach, discrete approaches model every single particle as a distinct entity and represent granular material as an idealized assembly of particles. This makes the discrete approach very good for investigating phenomena occurring at the length scale of particle diameter and simulating the bulk behavior of particles.
Does this mean that a DEM package would be better for modeling with soils rather than an FEM package, since soils are granular